Code description
(see handbook for full description & use suggestions)

OB Category - Observed: not breeding evidence

O

Species (male or female) known to breed in the state but seen "passing through" (e.g., vultures, nesting gulls), a colonial species observed with no colony found in the block, or a bird seen in unsuitable nesting habitat; all within safe dates.

PO Category - possible breeding evidence

X

Species (male or female) seen or heard in suitable nesting habitat within safe dates but no further evidence of breeding is uncovered. This includes a single drumming woodpecker, although the species must be seen to identify the woodpecker.

PR Category - probable breeding evidence

P

A pair (male and female together) seen in suitable nesting habitat within safe dates.

S

Permanent territory presumed through song, heard at same location on at least 2 occasions (both within safe dates), 7 days or more apart. This can be used for drumming woodpeckers, although the species must be seen to be identify the woodpecker.

T

Permanent territory presumed through defense of territory (often a male chasing individuals of the same species) within safe dates.

A

Agitated behavior or anxiety calls from adult observed within safe dates. These calls are frequently directed at cats or snakes.

C

Courtship behavior or copulation; OK to use outside of safe dates.

N

Visiting probable nest site within safe dates.

B

Building nests by wrens or excavation of holes by woodpeckers within safe dates.

CO Category - confirmed evidence of breeding

ON

Occupied nest. Adult seen sitting on nest and likely incubating eggs or brooding hatchlings. No eggs or young seen.

CN

Carrying nesting material such as sticks, grass, bark, etc. Not to be used for wrens, crows, or colonial species for which its colony is not found (e.g., Great Blue Heron).

NB

Nest building at the actual nest site by any species except wrens and woodpeckers.